It's faster these days. And it's not.

Meaning the level of detail we expect has gone up.
Google how long it takes for rendering frames for Pixar.. and that's an animation.

Optimus Prime will be life size on IMAX screens in many forest fight shots.
Imax frames take about 6 times longer than anamorphic to render.
IMAX frame render times: As high as 72 hours per frame!